Mumbai: Extending its gains for the third straight session, the rupee on Tuesday gained 11 paise to hit a fresh over 18-week high of 53.36 against the US dollar on fag-end selling of the American currency by exporters.

The rupee opened higher at 53.38 per dollar against last close of 53.47 at the Interbank Foreign Exchange (Forex) market. But it soon fell to a low of 53.63 on dollar demand from importers, mainly oil refiners, to meet their month-end requirements and also initial hesitancy in local equities.

However, sudden dollar selling by exporters and heavy capital inflows later aided the rupee to bounce back to a high of 53.31 before settling at 53.36, a gain of 11 paise, or 0.21 percent.

Meanwhile, the BSE benchmark Sensex today ended up by just 21.07 points, or 0.11 percent at 18,694.41.

Foreign Institutional Investors (FIIs) pumped in USD 310.02 million yesterday, after injecting USD 458.57 million last Friday as per Sebi data.

"The rupee put up a mixed performance primarily gaining on the policy reforms such as the SEB (state electricity board) restructuring and the disinvestment sale of RCF shall aid improvement in government finances. Rupee later reversed its intra-day losses on dollar selling by exporters," Alpari Financial Services (India) CEO Pramit Brahmbhatt said.

The dollar index, a gauge of six major currencies, was down by 0.01 percent, while New York crude oil was quoting below USD 93 a barrel in Europe today.

"The rupee started the day on a firm note but later traded on lower note after morning session as European debt concerns continued to persist with Spain is delaying the ESM bailout.

"Recent data from Germany showing a drop in the business confidence index also pressurised the currency. It recovered at the fag-end to close in positive," AbhishekGoenka, founder and CEO, India Forex Advisors, said.

The premium for the forward dollar closed better on fresh payments by banks and corporates.

The benchmark six-month forward dollar premium payable in February finished up at 141-1/2-143-1/2 paise from overnight close of 140-142 paise.

The premium for far-forward contracts maturing in August also inched up to 288-290 paise from 287-289 paise.

The RBI has fixed the reference rate for the US dollar at 53.5340 and for euro at 69.0295.

The rupee remained firm against the pound sterling to 86.58 from Monday's close of 86.69 and improved further to 68.99 per euro from 69.13. It, however, declined further against the Japanese yen to 68.60 per 100 yen from previous close of 68.52.